1 /*
2  * checkconf/unbound-checkconf.c - config file checker for unbound.conf file.
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * The config checker checks for syntax and other errors in the unbound.conf
40  * file, and can be used to check for errors before the server is started
41  * or sigHUPped.
42  * Exit status 1 means an error.
43  */
44 
45 #include "config.h"
46 #include "util/log.h"
47 #include "util/config_file.h"
48 #include "util/module.h"
49 #include "util/net_help.h"
50 #include "util/regional.h"
51 #include "iterator/iterator.h"
52 #include "iterator/iter_fwd.h"
53 #include "iterator/iter_hints.h"
54 #include "validator/validator.h"
55 #include "services/localzone.h"
56 #include "sldns/sbuffer.h"
57 #ifdef HAVE_GETOPT_H
58 #include <getopt.h>
59 #endif
60 #ifdef HAVE_PWD_H
61 #include <pwd.h>
62 #endif
63 #ifdef HAVE_SYS_STAT_H
64 #include <sys/stat.h>
65 #endif
66 #ifdef HAVE_GLOB_H
67 #include <glob.h>
68 #endif
69 #ifdef WITH_PYTHONMODULE
70 #include "pythonmod/pythonmod.h"
71 #endif
72 
73 /** Give checkconf usage, and exit (1). */
74 static void
75 usage(void)
76 {
77 	printf("Usage:	unbound-checkconf [file]\n");
78 	printf("	Checks unbound configuration file for errors.\n");
79 	printf("file	if omitted %s is used.\n", CONFIGFILE);
80 	printf("-o option	print value of option to stdout.\n");
81 	printf("-f 		output full pathname with chroot applied, eg. with -o pidfile.\n");
82 	printf("-h		show this usage help.\n");
83 	printf("Version %s\n", PACKAGE_VERSION);
84 	printf("BSD licensed, see LICENSE in source package for details.\n");
85 	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
86 	exit(1);
87 }
88 
89 /**
90  * Print given option to stdout
91  * @param cfg: config
92  * @param opt: option name without trailing :.
93  *	This is different from config_set_option.
94  * @param final: if final pathname with chroot applied has to be printed.
95  */
96 static void
97 print_option(struct config_file* cfg, const char* opt, int final)
98 {
99 	if(strcmp(opt, "pidfile") == 0 && final) {
100 		printf("%s\n", fname_after_chroot(cfg->pidfile, cfg, 1));
101 		return;
102 	}
103 	if(!config_get_option(cfg, opt, config_print_func, stdout))
104 		fatal_exit("cannot print option '%s'", opt);
105 }
106 
107 /** check if module works with config */
108 static void
109 check_mod(struct config_file* cfg, struct module_func_block* fb)
110 {
111 	struct module_env env;
112 	memset(&env, 0, sizeof(env));
113 	env.cfg = cfg;
114 	env.scratch = regional_create();
115 	env.scratch_buffer = sldns_buffer_new(BUFSIZ);
116 	if(!env.scratch || !env.scratch_buffer)
117 		fatal_exit("out of memory");
118 	if(!(*fb->init)(&env, 0)) {
119 		fatal_exit("bad config for %s module", fb->name);
120 	}
121 	(*fb->deinit)(&env, 0);
122 	sldns_buffer_free(env.scratch_buffer);
123 	regional_destroy(env.scratch);
124 }
125 
126 /** check localzones */
127 static void
128 localzonechecks(struct config_file* cfg)
129 {
130 	struct local_zones* zs;
131 	if(!(zs = local_zones_create()))
132 		fatal_exit("out of memory");
133 	if(!local_zones_apply_cfg(zs, cfg))
134 		fatal_exit("failed local-zone, local-data configuration");
135 	local_zones_delete(zs);
136 }
137 
138 /** emit warnings for IP in hosts */
139 static void
140 warn_hosts(const char* typ, struct config_stub* list)
141 {
142 	struct sockaddr_storage a;
143 	socklen_t alen;
144 	struct config_stub* s;
145 	struct config_strlist* h;
146 	for(s=list; s; s=s->next) {
147 		for(h=s->hosts; h; h=h->next) {
148 			if(extstrtoaddr(h->str, &a, &alen)) {
149 				fprintf(stderr, "unbound-checkconf: warning:"
150 				  " %s %s: \"%s\" is an IP%s address, "
151 				  "and when looked up as a host name "
152 				  "during use may not resolve.\n",
153 				  s->name, typ, h->str,
154 				  addr_is_ip6(&a, alen)?"6":"4");
155 			}
156 		}
157 	}
158 }
159 
160 /** check interface strings */
161 static void
162 interfacechecks(struct config_file* cfg)
163 {
164 	int d;
165 	struct sockaddr_storage a;
166 	socklen_t alen;
167 	int i, j;
168 	for(i=0; i<cfg->num_ifs; i++) {
169 		if(!extstrtoaddr(cfg->ifs[i], &a, &alen)) {
170 			fatal_exit("cannot parse interface specified as '%s'",
171 				cfg->ifs[i]);
172 		}
173 		for(j=0; j<cfg->num_ifs; j++) {
174 			if(i!=j && strcmp(cfg->ifs[i], cfg->ifs[j])==0)
175 				fatal_exit("interface: %s present twice, "
176 					"cannot bind same ports twice.",
177 					cfg->ifs[i]);
178 		}
179 	}
180 	for(i=0; i<cfg->num_out_ifs; i++) {
181 		if(!ipstrtoaddr(cfg->out_ifs[i], UNBOUND_DNS_PORT, &a, &alen) &&
182 		   !netblockstrtoaddr(cfg->out_ifs[i], UNBOUND_DNS_PORT, &a, &alen, &d)) {
183 			fatal_exit("cannot parse outgoing-interface "
184 				"specified as '%s'", cfg->out_ifs[i]);
185 		}
186 		for(j=0; j<cfg->num_out_ifs; j++) {
187 			if(i!=j && strcmp(cfg->out_ifs[i], cfg->out_ifs[j])==0)
188 				fatal_exit("outgoing-interface: %s present "
189 					"twice, cannot bind same ports twice.",
190 					cfg->out_ifs[i]);
191 		}
192 	}
193 }
194 
195 /** check acl ips */
196 static void
197 aclchecks(struct config_file* cfg)
198 {
199 	int d;
200 	struct sockaddr_storage a;
201 	socklen_t alen;
202 	struct config_str2list* acl;
203 	for(acl=cfg->acls; acl; acl = acl->next) {
204 		if(!netblockstrtoaddr(acl->str, UNBOUND_DNS_PORT, &a, &alen,
205 			&d)) {
206 			fatal_exit("cannot parse access control address %s %s",
207 				acl->str, acl->str2);
208 		}
209 	}
210 }
211 
212 /** true if fname is a file */
213 static int
214 is_file(const char* fname)
215 {
216 	struct stat buf;
217 	if(stat(fname, &buf) < 0) {
218 		if(errno==EACCES) {
219 			printf("warning: no search permission for one of the directories in path: %s\n", fname);
220 			return 1;
221 		}
222 		perror(fname);
223 		return 0;
224 	}
225 	if(S_ISDIR(buf.st_mode)) {
226 		printf("%s is not a file\n", fname);
227 		return 0;
228 	}
229 	return 1;
230 }
231 
232 /** true if fname is a directory */
233 static int
234 is_dir(const char* fname)
235 {
236 	struct stat buf;
237 	if(stat(fname, &buf) < 0) {
238 		if(errno==EACCES) {
239 			printf("warning: no search permission for one of the directories in path: %s\n", fname);
240 			return 1;
241 		}
242 		perror(fname);
243 		return 0;
244 	}
245 	if(!(S_ISDIR(buf.st_mode))) {
246 		printf("%s is not a directory\n", fname);
247 		return 0;
248 	}
249 	return 1;
250 }
251 
252 /** get base dir of a fname */
253 static char*
254 basedir(char* fname)
255 {
256 	char* rev;
257 	if(!fname) fatal_exit("out of memory");
258 	rev = strrchr(fname, '/');
259 	if(!rev) return NULL;
260 	if(fname == rev) return NULL;
261 	rev[0] = 0;
262 	return fname;
263 }
264 
265 /** check chroot for a file string */
266 static void
267 check_chroot_string(const char* desc, char** ss,
268 	const char* chrootdir, struct config_file* cfg)
269 {
270 	char* str = *ss;
271 	if(str && str[0]) {
272 		*ss = fname_after_chroot(str, cfg, 1);
273 		if(!*ss) fatal_exit("out of memory");
274 		if(!is_file(*ss)) {
275 			if(chrootdir && chrootdir[0])
276 				fatal_exit("%s: \"%s\" does not exist in "
277 					"chrootdir %s", desc, str, chrootdir);
278 			else
279 				fatal_exit("%s: \"%s\" does not exist",
280 					desc, str);
281 		}
282 		/* put in a new full path for continued checking */
283 		free(str);
284 	}
285 }
286 
287 /** check file list, every file must be inside the chroot location */
288 static void
289 check_chroot_filelist(const char* desc, struct config_strlist* list,
290 	const char* chrootdir, struct config_file* cfg)
291 {
292 	struct config_strlist* p;
293 	for(p=list; p; p=p->next) {
294 		check_chroot_string(desc, &p->str, chrootdir, cfg);
295 	}
296 }
297 
298 /** check file list, with wildcard processing */
299 static void
300 check_chroot_filelist_wild(const char* desc, struct config_strlist* list,
301 	const char* chrootdir, struct config_file* cfg)
302 {
303 	struct config_strlist* p;
304 	for(p=list; p; p=p->next) {
305 #ifdef HAVE_GLOB
306 		if(strchr(p->str, '*') || strchr(p->str, '[') ||
307 			strchr(p->str, '?') || strchr(p->str, '{') ||
308 			strchr(p->str, '~')) {
309 			char* s = p->str;
310 			/* adjust whole pattern for chroot and check later */
311 			p->str = fname_after_chroot(p->str, cfg, 1);
312 			free(s);
313 		} else
314 #endif /* HAVE_GLOB */
315 			check_chroot_string(desc, &p->str, chrootdir, cfg);
316 	}
317 }
318 
319 /** check configuration for errors */
320 static void
321 morechecks(struct config_file* cfg, const char* fname)
322 {
323 	warn_hosts("stub-host", cfg->stubs);
324 	warn_hosts("forward-host", cfg->forwards);
325 	interfacechecks(cfg);
326 	aclchecks(cfg);
327 
328 	if(cfg->verbosity < 0)
329 		fatal_exit("verbosity value < 0");
330 	if(cfg->num_threads <= 0 || cfg->num_threads > 10000)
331 		fatal_exit("num_threads value weird");
332 	if(!cfg->do_ip4 && !cfg->do_ip6)
333 		fatal_exit("ip4 and ip6 are both disabled, pointless");
334 	if(!cfg->do_ip6 && cfg->prefer_ip6)
335 		fatal_exit("cannot prefer and disable ip6, pointless");
336 	if(!cfg->do_udp && !cfg->do_tcp)
337 		fatal_exit("udp and tcp are both disabled, pointless");
338 	if(cfg->edns_buffer_size > cfg->msg_buffer_size)
339 		fatal_exit("edns-buffer-size larger than msg-buffer-size, "
340 			"answers will not fit in processing buffer");
341 #ifdef UB_ON_WINDOWS
342 	w_config_adjust_directory(cfg);
343 #endif
344 	if(cfg->chrootdir && cfg->chrootdir[0] &&
345 		cfg->chrootdir[strlen(cfg->chrootdir)-1] == '/')
346 		fatal_exit("chootdir %s has trailing slash '/' please remove.",
347 			cfg->chrootdir);
348 	if(cfg->chrootdir && cfg->chrootdir[0] &&
349 		!is_dir(cfg->chrootdir)) {
350 		fatal_exit("bad chroot directory");
351 	}
352 	if(cfg->chrootdir && cfg->chrootdir[0]) {
353 		char buf[10240];
354 		buf[0] = 0;
355 		if(fname[0] != '/') {
356 			if(getcwd(buf, sizeof(buf)) == NULL)
357 				fatal_exit("getcwd: %s", strerror(errno));
358 			(void)strlcat(buf, "/", sizeof(buf));
359 		}
360 		(void)strlcat(buf, fname, sizeof(buf));
361 		if(strncmp(buf, cfg->chrootdir, strlen(cfg->chrootdir)) != 0)
362 			fatal_exit("config file %s is not inside chroot %s",
363 				buf, cfg->chrootdir);
364 	}
365 	if(cfg->directory && cfg->directory[0]) {
366 		char* ad = fname_after_chroot(cfg->directory, cfg, 0);
367 		if(!ad) fatal_exit("out of memory");
368 		if(!is_dir(ad)) fatal_exit("bad chdir directory");
369 		free(ad);
370 	}
371 	if( (cfg->chrootdir && cfg->chrootdir[0]) ||
372 	    (cfg->directory && cfg->directory[0])) {
373 		if(cfg->pidfile && cfg->pidfile[0]) {
374 			char* ad = (cfg->pidfile[0]=='/')?strdup(cfg->pidfile):
375 				fname_after_chroot(cfg->pidfile, cfg, 1);
376 			char* bd = basedir(ad);
377 			if(bd && !is_dir(bd))
378 				fatal_exit("pidfile directory does not exist");
379 			free(ad);
380 		}
381 		if(cfg->logfile && cfg->logfile[0]) {
382 			char* ad = fname_after_chroot(cfg->logfile, cfg, 1);
383 			char* bd = basedir(ad);
384 			if(bd && !is_dir(bd))
385 				fatal_exit("logfile directory does not exist");
386 			free(ad);
387 		}
388 	}
389 
390 	check_chroot_filelist("file with root-hints",
391 		cfg->root_hints, cfg->chrootdir, cfg);
392 	check_chroot_filelist("trust-anchor-file",
393 		cfg->trust_anchor_file_list, cfg->chrootdir, cfg);
394 	check_chroot_filelist("auto-trust-anchor-file",
395 		cfg->auto_trust_anchor_file_list, cfg->chrootdir, cfg);
396 	check_chroot_filelist_wild("trusted-keys-file",
397 		cfg->trusted_keys_file_list, cfg->chrootdir, cfg);
398 	check_chroot_string("dlv-anchor-file", &cfg->dlv_anchor_file,
399 		cfg->chrootdir, cfg);
400 	/* remove chroot setting so that modules are not stripping pathnames*/
401 	free(cfg->chrootdir);
402 	cfg->chrootdir = NULL;
403 
404 	if(strcmp(cfg->module_conf, "iterator") != 0
405 		&& strcmp(cfg->module_conf, "validator iterator") != 0
406 		&& strcmp(cfg->module_conf, "dns64 validator iterator") != 0
407 		&& strcmp(cfg->module_conf, "dns64 iterator") != 0
408 #ifdef WITH_PYTHONMODULE
409 		&& strcmp(cfg->module_conf, "python iterator") != 0
410 		&& strcmp(cfg->module_conf, "python validator iterator") != 0
411 		&& strcmp(cfg->module_conf, "validator python iterator") != 0
412 		&& strcmp(cfg->module_conf, "dns64 python iterator") != 0
413 		&& strcmp(cfg->module_conf, "dns64 python validator iterator") != 0
414 		&& strcmp(cfg->module_conf, "dns64 validator python iterator") != 0
415 		&& strcmp(cfg->module_conf, "python dns64 iterator") != 0
416 		&& strcmp(cfg->module_conf, "python dns64 validator iterator") != 0
417 #endif
418 #ifdef USE_CACHEDB
419 		&& strcmp(cfg->module_conf, "validator cachedb iterator") != 0
420 		&& strcmp(cfg->module_conf, "cachedb iterator") != 0
421 		&& strcmp(cfg->module_conf, "dns64 validator cachedb iterator") != 0
422 		&& strcmp(cfg->module_conf, "dns64 cachedb iterator") != 0
423 		&& strcmp(cfg->module_conf, "python dns64 cachedb iterator") != 0
424 		&& strcmp(cfg->module_conf, "python dns64 validator cachedb iterator") != 0
425 		&& strcmp(cfg->module_conf, "dns64 python cachedb iterator") != 0
426 		&& strcmp(cfg->module_conf, "dns64 python validator cachedb iterator") != 0
427 		&& strcmp(cfg->module_conf, "python cachedb iterator") != 0
428 		&& strcmp(cfg->module_conf, "python validator cachedb iterator") != 0
429 		&& strcmp(cfg->module_conf, "cachedb python iterator") != 0
430 		&& strcmp(cfg->module_conf, "validator cachedb python iterator") != 0
431 		&& strcmp(cfg->module_conf, "validator python cachedb iterator") != 0
432 #endif
433 		) {
434 		fatal_exit("module conf '%s' is not known to work",
435 			cfg->module_conf);
436 	}
437 
438 #ifdef HAVE_GETPWNAM
439 	if(cfg->username && cfg->username[0]) {
440 		if(getpwnam(cfg->username) == NULL)
441 			fatal_exit("user '%s' does not exist.", cfg->username);
442 #  ifdef HAVE_ENDPWENT
443 		endpwent();
444 #  endif
445 	}
446 #endif
447 	if(cfg->remote_control_enable && cfg->remote_control_use_cert) {
448 		check_chroot_string("server-key-file", &cfg->server_key_file,
449 			cfg->chrootdir, cfg);
450 		check_chroot_string("server-cert-file", &cfg->server_cert_file,
451 			cfg->chrootdir, cfg);
452 		if(!is_file(cfg->control_key_file))
453 			fatal_exit("control-key-file: \"%s\" does not exist",
454 				cfg->control_key_file);
455 		if(!is_file(cfg->control_cert_file))
456 			fatal_exit("control-cert-file: \"%s\" does not exist",
457 				cfg->control_cert_file);
458 	}
459 
460 	localzonechecks(cfg);
461 }
462 
463 /** check forwards */
464 static void
465 check_fwd(struct config_file* cfg)
466 {
467 	struct iter_forwards* fwd = forwards_create();
468 	if(!fwd || !forwards_apply_cfg(fwd, cfg)) {
469 		fatal_exit("Could not set forward zones");
470 	}
471 	forwards_delete(fwd);
472 }
473 
474 /** check hints */
475 static void
476 check_hints(struct config_file* cfg)
477 {
478 	struct iter_hints* hints = hints_create();
479 	if(!hints || !hints_apply_cfg(hints, cfg)) {
480 		fatal_exit("Could not set root or stub hints");
481 	}
482 	hints_delete(hints);
483 }
484 
485 /** check config file */
486 static void
487 checkconf(const char* cfgfile, const char* opt, int final)
488 {
489 	char oldwd[PATH_MAX];
490 	struct config_file* cfg = config_create();
491 	if(!cfg)
492 		fatal_exit("out of memory");
493 	oldwd[0] = 0;
494 	if(!getcwd(oldwd, sizeof(oldwd))) {
495 		log_err("cannot getcwd: %s", strerror(errno));
496 		oldwd[0] = 0;
497 	}
498 	if(!config_read(cfg, cfgfile, NULL)) {
499 		/* config_read prints messages to stderr */
500 		config_delete(cfg);
501 		exit(1);
502 	}
503 	if(oldwd[0] && chdir(oldwd) == -1)
504 		log_err("cannot chdir(%s): %s", oldwd, strerror(errno));
505 	if(opt) {
506 		print_option(cfg, opt, final);
507 		config_delete(cfg);
508 		return;
509 	}
510 	morechecks(cfg, cfgfile);
511 	check_mod(cfg, iter_get_funcblock());
512 	check_mod(cfg, val_get_funcblock());
513 #ifdef WITH_PYTHONMODULE
514 	if(strstr(cfg->module_conf, "python"))
515 		check_mod(cfg, pythonmod_get_funcblock());
516 #endif
517 	check_fwd(cfg);
518 	check_hints(cfg);
519 	printf("unbound-checkconf: no errors in %s\n", cfgfile);
520 	config_delete(cfg);
521 }
522 
523 /** getopt global, in case header files fail to declare it. */
524 extern int optind;
525 /** getopt global, in case header files fail to declare it. */
526 extern char* optarg;
527 
528 /** Main routine for checkconf */
529 int main(int argc, char* argv[])
530 {
531 	int c;
532 	int final = 0;
533 	const char* f;
534 	const char* opt = NULL;
535 	const char* cfgfile = CONFIGFILE;
536 	log_ident_set("unbound-checkconf");
537 	log_init(NULL, 0, NULL);
538 	checklock_start();
539 #ifdef USE_WINSOCK
540 	/* use registry config file in preference to compiletime location */
541 	if(!(cfgfile=w_lookup_reg_str("Software\\Unbound", "ConfigFile")))
542 		cfgfile = CONFIGFILE;
543 #endif /* USE_WINSOCK */
544 	/* parse the options */
545 	while( (c=getopt(argc, argv, "fho:")) != -1) {
546 		switch(c) {
547 		case 'f':
548 			final = 1;
549 			break;
550 		case 'o':
551 			opt = optarg;
552 			break;
553 		case '?':
554 		case 'h':
555 		default:
556 			usage();
557 		}
558 	}
559 	argc -= optind;
560 	argv += optind;
561 	if(argc != 0 && argc != 1)
562 		usage();
563 	if(argc == 1)
564 		f = argv[0];
565 	else	f = cfgfile;
566 	checkconf(f, opt, final);
567 	checklock_stop();
568 	return 0;
569 }
570